diff --git a/CMakeLists.txt b/CMakeLists.txt
index b0ee7a2..ad24d32 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -214,11 +214,8 @@ else()
   endif()
 endif()
 
-if (Git_FOUND)
-  execute_process(COMMAND ${GIT_EXECUTABLE} rev-parse --abbrev-ref HEAD
-                  WORKING_DIRECTORY ${cryptopp-cmake_SOURCE_DIR}
-                  OUTPUT_VARIABLE cryptopp_GIT_BRANCH)
-  string(STRIP ${cryptopp_GIT_BRANCH} cryptopp_GIT_BRANCH)
+if(CRTPTOPP_GIT_BRANCH)
+    set(cryptopp_GIT_BRANCH ${CRTPTOPP_GIT_BRANCH})
 else()
   set(cryptopp_GIT_BRANCH "master")
 endif()